Slide-valve



(No Model.)

W. J, THOMAS.

SLIDE VALVE.

Patented July 3, 1888.

witnesses;

UNITED STATES PATENT OFFICE.

XVILLIAM J. THOMAS, OF SAUGELITO, CALIFORNIA.

SLIDE-VALVE.

SPECIFICATION forming part of Letters Patent No. 385,431, dated July 3,1888.

Application filed January 5, 1888.

To all whom it may concern.-

Be it known that 1, WILLIAM J. THOMAS, a citizen of the United States,residing in Saucelito, in the county of Marin and State of California,have invented certain new and useful Improvements in Slide-Valves forSteam- Engines; and I do hereby declare that the following is a full,clear, and exact description of my said invention, reference being hadto the drawings that accompany and form part of this specification.

The object of my invention is to convert an ordinary slide-valve into abalance slidevalve, and I accomplish this object by constructing andapplying bearing-rings having conical surfaces between the back of theslidevalve and the steam-chest, substantially after the manner explainedand set forth in the following description, in which the accompanyingdrawings are referred to by figures and letters.

Figure l of the said drawings is a vertical section taken longitudinallythrough a slidevalve and steam-chest to which my improvement is applied.Fig. 2 is a top view of the valve balance-cone and bearing-ring. Fig. 3shows the parts in detail. Figs. 4 and 5 represent a modification inwhich two split rings breakingjoints are used in place of the singlering.

A represents an ordinary slide-valve, and B the top or cover of itschamber.

O is a plate bolted on the back of the valve, or formed with the valveas a part of it, and having a circular groove, O on the upper facesurrounding a standing cone, D. The top of the cone is fiat and thesurface of the cone is the inner wall of the groove. Its height orthickness is also somewhat less than the space between the back of thevalve and the cover 13, so that when the valve is 011 its seat the topsurface of the cone will clear the cover. A space of three-sixteenths ofan inch is sufficient to be left between these surfaces.

'E is an expansible ring with its internal face tapered to fit closelyaround and against the cone to form a steam-tight joint between them.Its exterior diameter is somewhat less Serial No. 259.9l1. (No model.)

than that of the groove 0, to leave a steamspace within the groovebetween the ring and the outer wall of the groove. The ring is split ate, and the ends are so formed that an overlap-joint is produced, whichbreaks both vertically and horizontally, as shown in Fig. 3. The topface of this ring should stand at least one-eighth of an inch above thetop face of the cone, while its lower face should clear the bottom ofthe groove under the greatest pressure that will be brought upon the topof the ring. When the valve is seated and the cover bolted down, the topface of this ring forms the bearing-surface of the back of the valve andthe top of the cone sets clear of the cover.

Instead of the single bearing'riug E, two split rings, E E, Fig. 4, canbe used, the inner ring being tapered to fit the cone D, and the outerring fitted closely around the taper ring to cover the joint E". The tworings are locked together by a rib or spline, f, on one and acorresponding groove in the other. In either construction the taperingsurface of the expansible ring is held closely against the face of thecone by virtue of the elastic quality of the ring and its expansibility.As thus constructed and applied, it will be seen that the face of thecone on the valve and the conical surface of the ring constitute abearing-surface that is self-adjusting in several directions. Thesteam-pressure serves to keep the bearing-ring up to its seat againstthe cover, as well as to hold the working-faces of the parts tightlytogether. The bearing-surface on the back of the valve is thereforeuniversally adjustable in all directions horizon tally, while theexpansibility of the bearing ring compensates for any vertical movement.The valve seats evenly, therefore, under all conditions.

Having thus fully described my invention, what I claim, and desire tosecure by Letters Patent, is

1. The combination, with a slidevalve, of a top plate having an annulargroove in it, the inner wall of which groove is conical, as shown anddescribed, and an expansive ring,

E, tapered to lit the conical wall and of a size to stand above theupper edge thereof, as set forth.

both vertically and horizontally its point of division, as set forth.

In testimony that I claim the foregoing I 2. The combination, with aslide-valve, of have hereunto set my hand and seal.

5 a top plate having an annular groove in it,

the inner Wall of which is conical, and an expansible ring, E, taperedto fitand stand above the face of the top plate and breaking joints WM.J. THOMAS. [L. s.] Witnesses:

O. W. M. SMITH, CHAs. E. IQELLY.

